I first got this realization when I started using grey scale mode for my phone at night. A “good to bad” scale in an app became unintelligible. Since then I try to consider colorblindness if I design stuff myself. It’s fantastic if color scales carry meaning in both their colour but also the same meaning in their lightness, so everyone can understand them the same.
I’m afraid you actually unlearned to write. Are you sure you really can’t read what I’m saying?